In the prior art, a Mobile Node (MN) on the home network uses a Home Address (HoA) to communicate with a Correspondent Node (CN). When the MN moves to a visited network, the MN obtains an address, namely, a Care-of Address (CoA), from the visited network. The MN sends a binding update message that carries the CoA to a Home Agent (HA). Binding entries between the HoA and the CoA of the MN are created on the HA, and a bidirectional tunnel between the HA and the MN is set up. After receiving the registration request, the HA encapsulates the Internet Protocol (IP) packet that needs to be forwarded to the MN. The source address of the outer packet is the address of the HA, and the destination address of the outer packet is the CoA. The HA forwards the encapsulated packet to the MN through a tunnel. When sending a packet, the MN uses the CoA. The source address of the outer packet is the CoA, and the destination address of the outer packet is the address of the HA. The source address of the inner packet is the HoA, and the destination address of the inner packet is the address of the CN. The HA decapsulates the received packet, and forwards the inner packet to the CN.
The Proxy Mobile Internet Protocol Version 6 (PMIPv6) protocol is an extension of the Mobile Internet Protocol Version 6 (MIPv6): A Mobile Access Gateway (MAG) simulates the home link, and notifies a Home Network Prefix (HNP, HoA prefix) to the MN so that the MN believes that the MN is always on the home link; in place of the MN, the MAG sends a registration packet to the LMA. The LMA is equivalent to an HA in MIPv6. It creates binding buffer entries between the HNP and the MAG interface address (Proxy-CoA) on the LMA, and sets up a bidirectional tunnel for transmitting the packet of the MN between the MAG and the LMA. The process of receiving and sending the packet is as follows:
The peer node sends a packet to the HoA of the MN. The packet is intercepted by the LMA. Afterward, the LMA queries the binding list according to the HNP, and sends the packet to the MAG through the tunnel between the LMA and the MAG. The MAG de-tunnels the packet and sends the packet to the MN according to the destination address of the packet. When the MN sends a packet to the peer node, the MAG encapsulates the received packet, adds an outer packet (including the source address), and then sends the packet to the LMA through the tunnel between the MAG and the LMA. The LMA strips the outer packet, and forwards the inner packet to the peer node.
In the existing Proxy Mobile Internet Protocol (PMIP) domain, when the MN accesses the network, to enable the MN to support the mobility service, the MAG needs to perform Proxy Binding Update (PBU) registration. The registration process is as follows:
1. The MN accesses the network.
2. After the access authentication process is completed, the Authentication, Authorization and Accounting (AAA) server returns a message to the MAG. The message carries MN configuration information, for example, LMA address, Network Access Identifier (NAI) of the MN.
3. In place of the MN, the MAG sends a PBU request to the LMA.
4. The LMA returns a Proxy Binding Acknowledge (PBA) message that carries the HNP of the MN.
5. The MAG sends a Route Advertisement (RA) that carries the HNP of the MN to the MN.
In the process of implementing the present invention, the inventor finds at least the following defects in the prior art:
The registration process is unable to support network sharing or load balancing properly. When the LMA returns a registration failure message due to overload or local management policy adjustment, the MN may regress to the simple Internet Protocol Version 6 (IPv6) service or be rejected to access service, and is unable to support the mobility service of the MN properly.